Generally, a wind turbine includes a tower, a nacelle mounted on the tower, and a rotor coupled to the nacelle. The rotor typically includes a rotatable hub and a plurality of rotor blades coupled to and extending outwardly from the hub. Each rotor blade may be spaced about the hub so as to facilitate rotating the rotor to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy.
Various batteries are often used within a wind turbine to supply electrical power to wind turbine components. For example, one or more pitch batteries are often stored within the hub so as to supply power to the pitch adjustment mechanisms used to pitch the rotor blades. As with all batteries, the pitch batteries have a limited lifetime across which they may supply power. Thus, the pitch batteries must be periodically replaced to avoid pitch system failures.
Current replacement strategies employ a fixed replacement schedule in which the pitch batteries are replaced at a predetermined interval, such as every three years. This predetermined interval typically corresponds to a time period beyond which it is believed that each battery's lifetime will extend regardless of the operating conditions of the wind turbine. Accordingly, such battery replacement strategies fail to take into account the variations in battery lifetimes that exist due to changing operating conditions, particularly changes in the ambient air temperature. As a result, batteries are often removed too early, thereby increasing both the operating costs and the downtime of a wind turbine over an extended period of time.
Accordingly, improved methods or strategies for scheduling the replacement of wind turbine batteries would be welcomed in the technology.